369 results about "Intra mode" patented technology

Embodiments of the present disclosure provide a decoding method, an encoding method, and a storage medium. In the decoding method provided in embodiments of the present disclosure, first transform is performed on first transform coefficients of a current block based on a transform set corresponding to a first intra prediction mode, and the first intra prediction mode is designed to be any one of: an intra prediction mode derived from a decoder side intra mode derivation (DIMD) mode for a prediction block of the current block, an intra prediction mode derived from the DIMD mode for an output vector of an optimal matrix based intra prediction (MIP) mode for predicting the current block, an intra prediction mode derived from the DIMD mode for reconstructed samples in a first template region adjacent to the current block, and an intra prediction mode derived from a template based intra mode derivation (TIMD) mode.

An example device for decoding video data includes a memory configured to store video data; and a processing system comprising one or more processors implemented in circuitry, the processing system being configured to: generate a prediction block for a current block of video data using a neural network; determine an equivalent intra mode for the prediction block from a set of available intra-prediction modes using decoder-side intra mode derivation (DIMD), the equivalent intra mode representing one of the intra-prediction modes that would generate an intra-prediction block that would best match the prediction block generated using the neural network; decode a residual block for the current block of the video data based on the equivalent intra mode; and combine the prediction block with the residual block to decode the current block of the video data.

A video encoder and video decoder may determine to code a block of video data using a non-directional intra mode. The video encoder and video decoder may determine a secondary transform from a secondary transform set for the block, and perform a transform process on the block of video data using the secondary transform. For non-directional intra prediction modes, the secondary transform set has a first number of transform kernels that is less than a second number of transform kernels in the secondary transform set for other blocks coded using a directional intra mode.

A method and apparatus for generating an extended MPM (Most Probable Modes) list by adding the target DIMD candidate and said at least one neighbouring mode of the target DIMD candidate to an initial MPM list. A target DIMD candidate is determined for the current block based on a DIMD process using statistics or histogram of angle field derived from a template of the current block. At least one neighbouring mode of the target DIMD candidate is generated by adding an offset to a corresponding mode number of the target DIMD candidate, and wherein the offset corresponds to a non-zero integer. An extended MPM (Most Probable Modes) list is generated by adding the target DIMD candidate and said at least one neighbouring mode of the target DIMD candidate to an initial MPM list. The current block is encoded or decoded using information comprising the extended MPM list.

A method for implicitly deriving region-based intra-prediction is provided. A video coder receives data for a block of pixels to be encoded or decoded as a current block of a current picture of a video. The video coder identifies an above template region and a left template region of the current block among already-reconstructed pixels of the current picture. The video coder derives a first intra-prediction mode based on the above template region and a second intra-prediction mode based on the left template region. The video coder generates first and second predictors for the current block based on the first and second intra prediction modes. The video coder encodes or decodes the current block by using the first and second predictors to reconstruct the current block.

A video coder may code a flag indicating whether or not a neural network (NN)-based intra prediction mode is enabled before coding a decoder side intra mode derivation (DIMD) flag, and code a block of video data based on whether or not the NN-based intra prediction mode is enabled.

Methods and apparatus for video coding are disclosed. One method determines a prediction direction between vertical prediction and horizontal prediction for the current block based on a template of the current block or based on decoder side intra mode derivation (DIMD) using statistics or histogram of angle field derived from the template of the current block. According to another method, the current block is partitioned into a first region and a second region according to a region split. The first region is encoded or decoded based on inter coding. The second region is encoded or decoded according to intra coding. At least a part of region-spit parameters, a part of inter coding parameters, or a part of intra coding parameters are determined based on a template of the current block or based on DIMD using statistics or histogram of angle field derived from the template of the current block.

Provided is an image decoding method performed by a decoding apparatus, the image decoding method including receiving image information including at least one of decoder-side intra mode derivation (DIMD)-related information or template-based intra mode derivation (TIMD)-related information from a bitstream, deriving an intra prediction mode of a current block on the basis of the at least one of the DIMD-related information or the TIMD-related information, generating prediction samples of the current block on the basis of the intra prediction mode, and generating reconstructed samples of the current block on the basis of the prediction samples of the current block. The image information includes matrix-based intra prediction (MIP) flag information, the DIMD-related information includes DIMD flag information indicating whether a DIMD mode is applied to the current block, the TIMD-related information includes TIMD flag information indicating whether a TIMD mode is applied to the current block, and the DIMD flag information or the TIMD flag information is parsed after the MIP flag information.

Methods and apparatus for video coding. When a current intra angular prediction mode for the current block is not in the MPM list, a mode syntax related to a current intra prediction mode for the current block is signalled or parsed depending on first information derived according to DIMD or TIMD. A final intra predictor is generated based on second information comprising the first information and the mode syntax. The current block is encoded or decoded using a final mode derived based on information comprising the syntax.

A coded video bitstream is received. The coded video bitstream includes coded information of a current block in a current picture, the coded information indicates that the current block is coded by an intra prediction using an affine intra mode (AIM) model. The affine intra mode model for applying on the current block is determined. At least a first intra angular mode for a first sample in the current block and a second intra angular mode for a second sample in the current block are determined according to the affine intra mode model, the first intra angular mode is different from the second intra angular mode. The current block is reconstructed based on the intra prediction using the affine intra mode model, the first sample is predicted based on the first intra angular mode and the second sample is predicted based on the second intra angular mode.

A method of video processing is described. The method includes performing a conversion between a chroma block of a video region of a video picture of a video and a coded representation of the video according to a rule. The rule specifies that, due to the chroma block having a size M×N, the chroma block is disallowed to be represented in the coded representation using an intra coding mode. M and N are integers that indicate a width and a height of the chroma block, respectively. The intra coding mode includes coding the chroma block based on a previously coded video region of the video picture.

A method of deriving a Decoder-side Intra Mode Derivation (DIMD) predictor for respective samples of a coding unit (CU) of a picture, includes: splitting a template area adjacent to the CU into a plurality of template area regions; separately selecting no, one or more Intra Prediction Modes (IPMs) in each template area region, wherein the selection involves a selection out of the separately determined IPMs for the entire CU or for one or more regions of the CU; determining blending weights using the selected IPMs, and generating the DIMD predictor by blending at least the selected IPMs using the determined blending weights.

A method for performing template-based intra mode derivation (TIMD) with enhanced candidate intra-prediction modes is provided. A video coder determines a set of most probable modes (MPMs) for intra-coding the current block based on intra-prediction modes used to code neighboring blocks of the current block. The video coder determines a template of the current block among already-reconstructed pixels neighboring the current block. The video coder determines a set of candidate intra-prediction modes to include (i) the set of MPMs and (ii) one or more intra-prediction modes neighboring an MPM in the set of MPMs. The video coder derives an intra-prediction mode from the set of candidate intra-prediction modes based on the determined template and the set of candidate intra-prediction modes. The video coder encodes or decodes the current block by using the derived intra-prediction mode to generate an intra-prediction.

In a method, coded information of a current block in a current picture of a video is received from a coded video bitstream. The coded information indicates that the current block is partitioned into at least a first partition and a second partition based on a geometric partition mode (GPM). The first partition is associated with an intra block copy (IBC) prediction mode, and the second partition is associated with an intra prediction mode. Prediction mode information for a first subblock of a plurality of subblocks of the current block is stored. The prediction mode information includes one of a DC mode, a Planar mode, and an intra prediction mode based on whether the first subblock is associated with one of the IBC prediction mode, the intra prediction mode, and both the IBC prediction mode and the intra prediction mode.

An image decoding method performed by a decoding device includes: obtaining image information including prediction-related information from a bitstream; determining whether combined inter-picture merge and intra-picture prediction (CIIP) is applied to a current block, on the basis of the prediction-related information; deriving a prediction sample of the current block on the basis of it being determined that the CIIP is applied to the current block; and generating a reconstructed sample of the current block on the basis of the prediction sample, wherein the prediction sample of the current block is derived on the basis of an intra prediction sample and an inter prediction sample, wherein the intra prediction sample is derived on the basis of an intra prediction mode, wherein the intra prediction mode is derived on the basis of a decoder side intra mode derivation (DIMD) mode or a template-based inter mode derivation (TIMD) mode.

Devices, systems and methods for digital video coding, which includes matrix-based intra prediction methods for video coding, are described. In a representative aspect, a method for video processing includes performing a first determination whether a luma video block of a video is coded using a matrix based intra prediction (MIP) mode; performing a second determination that the luma video block is applicable for determining a chroma intra mode for a current chroma video block of the video; performing, based on the first determination and the second determination, a third determination about the chroma intra mode to be used for the current chroma video block; and performing, based on the third determination, a conversion between the current chroma video block and a bitstream representation of the current chroma video block.

A video coder is configured to determine a first set of transform sets and a second set of transform sets, determine, for a current block of video data coded using a non-directional intra mode, a list of intra prediction directions determined from a decoder-side intra mode derivation (DIMD) process applied to prediction block samples of the current block, determine, for the current block, a transform set from the second set of transform sets based on a second highest intra prediction direction in the list of intra prediction directions, and encode or decode the current block using a transform in the transform set.

A device may obtain a reference block associated with an inter prediction of a video block. The device may determine an intra-prediction mode associated with the video block based on one or more intra-prediction modes associated with the reference block. The device may decode or encode the video block based on the intra-prediction mode. In examples, the device may decode or encode the video block using an intra prediction and the inter prediction, and the intra prediction of the video block may be based on the intra-prediction mode. For example, combined intra-inter prediction (CIIP) may be enabled for the video block. CIIP for the video block may include the intra prediction of the video block and the inter prediction of the video block. The intra prediction of the video block may be based on the intra-prediction mode.

A video coding method using decoder-side intra mode derivation (DIMD) based on multiple histograms of gradients (HoGs) is provided. A video coder receives data to be encoded or decoded as a current block of a current picture of a video. The video coder derives a plurality of HoGs for different intra prediction angles. Different HoGs are derived based on different sets of reconstructed pixels neighboring the current block. The video coder selects a HoG from the plurality of HoGs. The video coder identifies one or more intra prediction modes based on the selected HoG. The video coder generates an intra-prediction of the current block based on the identified one or more intra prediction modes. The video coder encodes or decodes the current block by using the generated intra-prediction.

Methods and apparatuses for video decoding and video encoding and a method of processing visual media data are disclosed. The apparatus for video decoding includes processing circuitry that receives coded information indicating that a current block in a current picture is coded with a decoder-side intra mode derivation (DIMD) mode. A template of the current block includes reconstructed samples in the current picture and is adjacent to the current block. The template includes one of a left template and a top template. The processing circuitry determines a filter type from a plurality of filter types associated with the one of the left template and the top template, applies the DIMD mode to the template based on the determined filter type to determine one or more intra prediction modes for the current block, and reconstructs the current block according to the one or more intra prediction modes.

A method for decoder-side intra mode derivation (DIMD) by inheriting histogram of gradients (HoG) from neighborhood is provided. A video coder derives a current HoG for a current block by inheriting one or more HoGs from neighboring blocks in a vicinity of the current block. The inherited HoGs may include one or more augmented HoG that is derived without gradient calculation. The inherited HoGs may include one or more HoG that is re-generated for a neighboring block that already has a HoG that is stored and available for inheritance by the current block. The video coder identifies two or more intra-prediction directions based on the current HoG. The video coder encodes or decodes the current block by using the identified intra-prediction directions to generate a prediction of the current block.

The various implementations described herein include methods and systems for coding video. An example method of video decoding includes receiving a video bitstream comprising a plurality of blocks that includes a current block. The method also includes, for each neighboring block in a set of neighboring blocks of the current block, when the neighboring block is coded using a template-based intra prediction mode derivation (TIMD), populating a candidate list for the current block with an entry for the neighboring block, where at least one entry in the candidate list comprises a three-mode entry. The method further includes reconstructing the current block using an entry from the candidate list.

An image encoding / decoding method and apparatus, a recording medium storing a bitstream and a transmission method are provided. The image decoding method may comprise generating a derived intra prediction mode by performing decoder side intra mode derivation (DIMD) on a current block and storing the derived intra prediction mode. The current block is in a matrix based intra prediction (MIP) mode.

According to the present disclosure, a method by which a decoding device decodes an image comprises the steps of: acquiring a bit-stream including image information; deriving a decoder-side intra mode derivation (DIMD) mode for the current block; deriving an intra-prediction mode for the current block; generating prediction samples for the current block on the basis of the intra-prediction mode for the current block; and generating reconstructed samples for the current block on the basis of the prediction samples for the current block, wherein the intra-prediction mode for the current block is derived on the basis of whether the DIMD mode is applied to the current block.

A video coder determines, based on a first indication of a decoder-side intra mode derivation (DI MD) prediction mode being enabled for coding a current block: a first histogram of gradients (HoG) based on the current block; and a second HoG based on a neighboring block of the current block. A value is determined representing a similarity between the first HoG and the second HoG. Based on comparing the value with a threshold value, a set of parameters is selected, from a first set of parameters and a second set of parameters, for the DIMD prediction mode. The coder codes the current block using a DIMD predictor generated based on the set of parameters.

To enable better intra-prediction to reduce the amount of bits to communicate the apparatus or method uses a template-based intra mode derivation (TIMD) based on a candidate list comprising at least one TIMD merge candidate belonging to a previously decoded spatially non-adjacent block of the current block, wherein a TIMD merge candidate is a predictor to be combined with another predictor to form a merged predictor; comprising decoding from the compressed video data a candidate position indicator which specifies a TIMD merge candidate in the list.

Methods and systems are described for intra-prediction using template matching (TM) in video coding. The proposed methods include adaptive fusion when using template-based intra mode derivation using the most probable modes (TIMD), and fusion in intra mode prediction with template matching (Intra TMP).

A video coder (encoder or decoder) reorders a list of merge candidates. The list of merge candidates comprises a merge candidate comprising decoder-side intra mode derivation (DIMD) information or Template-based Intra Mode Derivation (TIMD) information associated with a spatially neighboring block of a current block in a current frame. The video coder determines an indicator of the merge candidate in the list of merge candidates and codes the current block based on the DIMD information of the merge candidate in the list of merge candidates according to the indicator.

A video coder (encoder or decoder) generates, for a current block in a current frame, a list of merge candidates. A merge candidate in the list comprises decoder side intra mode derivation (DIMD) information associated with a spatially neighboring block of the current block. The coder further determines an indicator of the merge candidate in the list of merge candidates and codes the current block based on the DIMD information of the merge candidate in the list of merge candidates according to the indicator.

Disclosed are an image encoding / decoding method and apparatus. The image decoding method includes decoding coding mode information of a current coding block, dividing the current coding block into at least one prediction block, and generating prediction samples of the at least one prediction block on the basis of the decoded coding mode, in which the coding mode information is information indicating any one mode among intra mode, inter mode, and hybrid mode.